1ZW7
Elimination of the C-cap in Ubiquitin Structure, Dynamics and Thermodynamic Consequences
Summary for 1ZW7
| Entry DOI | 10.2210/pdb1zw7/pdb |
| Descriptor | Ubiquitin (1 entity in total) |
| Functional Keywords | dynamics, thermodynamics, structural protein |
| Biological source | Saccharomyces cerevisiae (baker's yeast) |
| Total number of polymer chains | 1 |
| Total formula weight | 9177.36 |
| Authors | Ermolenko, D.N.,Dangi, B.,Gronenborn, A.M.,Makhatadze, G.I. (deposition date: 2005-06-03, release date: 2006-05-16, Last modification date: 2024-05-22) |
| Primary citation | Ermolenko, D.N.,Dangi, B.,Gvritishvili, A.,Gronenborn, A.M.,Makhatadze, G.I. Elimination of the C-cap in ubiquitin-structure, dynamics and thermodynamic consequences. Biophys.Chem., 126:25-35, 2007 Cited by PubMed Abstract: Single amino acid substitutions rarely produce substantial changes in protein structure. Here we show that substitution of the C-cap residue in the alpha-helix of ubiquitin with proline (34P variant) leads to dramatic structural changes. The resulting conformational perturbation extends over the last two turns of the alpha-helix and leads to enhanced flexibility for residues 27-37. Thermodynamic analysis of this ubiquitin variant using differential scanning calorimetry reveals that the thermal unfolding transition remains highly cooperative, exhibiting two-state behavior. Similarities with the wild type in the thermodynamic parameters (heat capacity change upon unfolding and m-value) of unfolding monitored by DSC and chemical denaturation suggests that the 34P variant has comparable buried surface area. The hydrophobic core of 34P variant is not packed as well as that of the wild type protein as manifested by a lower enthalpy of unfolding. The increased mobility of the polypeptide chain of this ubiquitin variant allows the transient opening of the hydrophobic core as evidenced by ANS binding. Taken together, these results suggest exceptional robustness of cooperativity in protein structures. PubMed: 16713063DOI: 10.1016/j.bpc.2006.03.017 PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
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